Primicaris Temporal range: Cambrian | |
---|---|
Artist's reconstruction | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | †Marrellomorpha |
Order: | †Acercostraca |
Genus: | †Primicaris Zhang et al 2003 |
Species: | †P. larvaformis |
Binomial name | |
†Primicaris larvaformis Zhang et al 2003 | |
Primicaris is genus of Cambrian arthropod from the Chengjiang biota of China and the Burgess Shale of Canada. It contains a single described species, P. larvaformis.
Description
Specimens range from 2.08 to 6.04 millimetres (3⁄32 to 1⁄4 in) in length, and 1.50 and 4.20 millimetres (1⁄16 and 5⁄32 in) in maximum width. The undivided subovate-shaped dorsal shield covered the entire body, and wrapped around the front edge of the carapace, forming a doublure structure. The midline of the carapace exhibited thickening. There is a pair of slender uniramous segmented antennae, as well as ten pairs of biramous limbs. The exopods of these limbs are flagellate and bear setae, with the exopods decreasing in size posteriorly. The endopods are poorly preserved.[1]
Taxonomy
Its specimens were once thought to be meraspids of Naraoia spinosa.[1] Although their phylogenetic position has been described as "problematic",[2] recent studies have suggested them to be marrellomorphs belonging to the subgroup Acercostraca.[3][4]
See also
References
- 1 2 Zhang, Xing-Liang; Han, Jian; Zhang, Zhi-Fei; Liu, Hu-Qin; Shu, De-Gan (May 2003). "Reconsideration of the supposed naraoiid larva from the Early Cambrian Chengjiang Lagerstatte, South China". Palaeontology. 46 (3): 447–465. doi:10.1111/1475-4983.00307. ISSN 0031-0239.
- ↑ Caron, Jean-Bernard; Gaines, Robert R.; Aria, Cédric; Mángano, M. Gabriela; Streng, Michael (2014-02-11). "A new phyllopod bed-like assemblage from the Burgess Shale of the Canadian Rockies". Nature Communications. 5 (1): 3210. Bibcode:2014NatCo...5.3210C. doi:10.1038/ncomms4210. ISSN 2041-1723. PMID 24513643.
- ↑ Legg, D.A. (2015-09-30). "The morphology and affinities of Skania fragilis (Arthropoda) from the middle Cambrian Burgess Shale". Bulletin of Geosciences: 509–518. doi:10.3140/bull.geosci.1532. ISSN 1802-8225.
- ↑ Moysiuk, Joseph; Izquierdo-López, Alejandro; Kampouris, George E.; Caron, Jean-Bernard (July 2022). "A new marrellomorph arthropod from southern Ontario: a rare case of soft-tissue preservation on a Late Ordovician open marine shelf". Journal of Paleontology. 96 (4): 859–874. doi:10.1017/jpa.2022.11. ISSN 0022-3360.